Current-voltage (I-V) characteristics of Al/p-ZnO:Li/LaB6 device, measured in voltage sweep mode, show unipolar resistive switching and monostable threshold switching (URS and MTS) for different bias voltage polarities. URS could be transformed to MTS by application of reverse bias voltage. With increasing number of cycles, URS is converted to bipolar resistive switching mode which is lost after certain number of cycles, and device turns into an ordinary resistor. Analysis of linear fitting I-V curves suggests that ohmic and space charge limited current laws are responsible for conductivity mechanism of Al/p-ZnO:Li/LaB6 device. (C) 2015 Elsevier B.V. All rights reserved.